High-power lasers are used in many cutting, etching, annealing, welding, drilling, and soldering applications. As in any materials-processing operations, efficiency can be a critical limiting factor in terms of expense and time; the lower the efficiency, the higher will be the cost and/or the slower will be the operation of the laser deployed to process a given material. The brightness and polarization of the laser beam can influence efficiency, and different materials (such as copper, aluminum, steel, and so forth) respond differently to beam polarization as they are processed. Moreover, the thicknesses of these materials can affect their polarization response. That is, the nature of a cut or weld may vary with the beam polarization depending on the material and its thickness. For example, a linearly polarized processing beam may be absorbed differently depending on the orientation of the beam's polarization with respect to the cut front. For this reason, laser-processing systems sometimes utilize circularly or randomly polarized laser output in order to avoid directionally dependent polarization responses. While that approach avoids the efficiency-degrading results of unfavorable polarization orientations, it likewise precludes the benefits of favorable orientations.
Accordingly, there is a need for improved systems and techniques for enhancing the efficiency of laser processing operations that exploit the varying responses to beam polarization that characterize different materials and material thicknesses.